I have a sony fm-am receiver STR-DE705 and two floor speakers with boss 400 wt midrange boss2500 woofer and two tweeters. They sound good and very clear but I don't feel like I'm getting the loudness out of em I want to hear. What can I purchase that will help me to achieve the loud bumping that I want
If you want louder you will need more power.
If you connect a speaker to line level converter to the speaker terminals of the Sony you can connect any power amplifier you want. Be aware that the power ratings on some amps aren't accurate. The quality of the amp will also affect the quality of the sound beyond just being louder.
If your budget is limited a used power amp might make sense.